Haswell HD 4600 has artifact and glitches (flickering) problem with many laptops and desktops due to hardware acceleration problem somehow. I’ve just installed Big Sur and tested Monterey on my HP M7- j120dx i7-4700mq with Haswell HD 4600 and the artifact appears only when using OpenCore to boot. Clover v5146 fix the problems with the same config almost. For some reasons, OpenCore use the same fix by Rehabman but still doesn’t work. The fix is simple, need to use Clover instead of OpenCore.